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Reduction of the metal centre in aqueous permanganate ion involves |
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Answer» 3 electrons in neutral medium `MnO_(4)^(-) + 2H_(2)O + 3e^(-) rarrMnO_(2) + 4OH^(-)` In alkaline medium `MnO_(4)^(-) + e^(-) rarr MnO_(4)^(2-)` But `MnO_(4)^(2-)` is further reduced to `MnO_(2)` as shown below `MnO_(4)^(2-)+ 2H_(2)O + 2E^(-) rarr MnO_(2) + 4OH^(-)` Complete reaction is `MnO_(4)^(2-) + 2H_(2)O+ 3e^(-) rarr MnO_(2) + 4OH^(-)` which is the same as that for neutral medium. In acidic medium `MnO_(4)^(-) + 8 H^(+) + 5e^(-) rarr Mn^(2+) + 4H_(2)O` HENCE, the number of electrons involved in the reductionof metalcentre in aqueous `MnO_(4)^(-)` ION in neutral, alkaline and acidicmedia are 3,3 and 5 respectively. |
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